Be aware that not all Ford 8 lug wheels are the same. Ford vans have a different hole pattern than the PU trucks, vans are fractional and truck are metric patterns. I forget the difference, but be aware when you are looking for wheels.
My DD has been a series of E350's for over 20 years and I like them a lot. Keep good tires on them and you will be fine. As to shocks, I have replaced them, but only after the stock ones are well used. I actually prefer Tokico over Bilsteins, and I have used both. Better ride by far with the Tokico's and way better price!
As to tire size, lifting a van is not what I want for various reasons, mainly safety, but it also makes it harder for passengers and loading the van. One thing I use is the rear wheel spacers that make the front and rear track the same width. Ford, in an cost saving move, uses a narrower old style PU rear end in the van, even though the vans front track is wider. You can buy the spacers on line and the stock lugs on the full floater axles are plenty long to install these. You get better handling both in general driving and in an emergency also.
Vans are good vehicles.
Doug